Hydraulic motor

ABSTRACT

Positive displacement hydraulic motor employing planetary mechanism and using pins placed in offset holes for coupling the orbiting member to the shaft; valve assemblies and control parts with inclined end faces which control the flow of fluid into and out of sets of expansible chambers, and vanes for delimiting the expansible chambers.

United States Patent Lusziig [451 Oct. 17, 1972 [54] HYDRAULIC MOTOR 3,561,893 2/l97l Baatrup ..4l8/6l [72] Inventor: Gavril T. Lusziig, Haledon,N.J.

. Primary Examiner-Carlton R. Croyle [73] Assignee. vwvesbster Electric Company, Racine, Assistant Examiner john J. vrablik [22] Filed: Dec. 21,1970 7 57 ABSTRACT [21] Appl' 100,186 Positive displacement hydraulic motor employing Related Applicafian Dam planetary mechanism and tising pins placed in offset vholes for coupling the orbiting member to the shaft; [62] Dmslo 850,937 1969 vvalve assemblies and control parts with inclined end abandoned faces which control the flow of fluid into and out of 52 us. Cl. ..418/61, 418/185, 418/187, 93 clambem and delmtmg 418/188 t e expans1 e c am ers. [51] Int. Cl ..F0lc l/02,- F030 3/00, F04c l/O2 [58] Field of Search ..4l8/6l, l85-l88 [56] References Cited 13 Claims, 8 Drawing Figures UNITED STATES PATENTS 2,713,828 7/1955 Huber... ..4l8/ol HYDRAULIC MOTOR This invention relates to positive displacement hydraulic motors, and is particularly directed to motors which, for their size, have a relatively high output torque for the pressure difference between the inlet and exhaust and is a division of copending U.S. Pat. ap-

plication Ser. No. 850,937, filed Aug. 18, 1969, now

abandoned.

Hydraulic motors employing planetary mechanisms to transmit the motion of a driving member to a driven member are known in the art. The planetary mechanism of presently used motors consists of a ring gear and a pinion, the pinion being placed in the interior of the ring gear and meshing with it. One of these two gear elements, when functioning as a fixed element relative to the casing will be referred to hereinafter as a fixed member; the other then being called orbiting member. The orbiting member has a motion which can be resolved into two components. One translational motion of the orbiting member, which is defined by the path described by the axis of the orbiting member around the axis of the fixed member. This motion is referred to as orbiting motion. The second component being a rotation of the orbitingmember around its own axis is referred to as rotation of the orbiting member.

In existing motors, the'volumes delimited by the surface of the teeth of the fixed member, by the surface of the teeth of the orbiting member, and by walls provided to seal these volumes on their frontal surfaces, form expansible chambers, some of which are expanding while others are contracting at the same time.

In existing motors the motion of the orbiting member is caused by the force resulting from the inlet pressure of the driving fluid, acting upon a portion of the surface of the teeth of the orbiting member. The active profile of the teeth of the fixed member and of the orbiting member have to perform two distinct functions: first, a gearing-and-bearing function, transmitting forces between the fixed member and the orbiting member and second, a sealing function of the expansible chambers.

The motor according to this invention provides improved means for transmitting the motion of the orbiting member to the output shaft. It also provides improved valving arrangement to connect the proper expansible chambers to the respective ports. It also provides means for sealing the expansible chambers, distinct from the elements which have the gearing-andbearing function in transmitting the forces between the fixed member and the orbiting member.

Two preferred embodiments of the invention are hereinafter particularly described, one called hereinafter motor A and another, called hereinafter motor B, in reference to the drawings, in which:

FIG. 1 is a longitudinal cross-sectional view of the motor A taken along the line 1-1 in FIG. 2;

FIG. 2 is a cross-sectional view of the motor A taken along the line 22 in FIG. 1;

FIG. 3 is a cross-sectional view of the motor A taken along the line 33 in FIG. 1;

FIG. 4 is a partial sectional view of the motor A taken along the line 44 in FIG. 1;

FIG. 5 is a longitudinal cross-sectional view of the motor B taken along the line 5-5 in FIG. 6;

FIG. 6 is a cross-sectional view of the motor B taken along the line 66 in FIG. 5;

FIG. 7 is a cross-sectional view of the motor B taken along the line 7-7 in FIG. 5; I

FIG. 8 is a partial sectional view of the motor B taken along the line 8-8 in FIG. 5.

Referring now to FIGS. 1 through 4 of the drawings, the hydraulic motor A is shown having a casing I consisting of parts 1, 2, 3, 4 and 5, held together by the fasteners 6. The end cap 1 has two openings extending through it, one being an inlet port 7 and another an exhaust port 8. A shaft 9 has a driven portion enclosed by the casing I and an output portion extending out through an opening in the end cap 5. The output portion of the shaft is provided with any conventional means, not shown in the drawings for use in connecting the output portion to a load. The shaft 9 is rotatable with respect to the casing I and isformed with a cylindrical surface 10, which is in contact with needle bearings 11 disposed in an outer race 12 supported by the casing I. The shaft is also formed with a flanged face 13, which acts as a frontal wall for a series of expansible chambers which will be hereinafter described. The shaft 9 has an extension which passes through a central hole in an orbiting member 14, which is placed offset with respect to the shaft 9 within the casing I. The end of the extension of the shaft 9 is fastened to a disc 15. The shaft 9 is also formed with a longitudinal hole 16, and transverse holes 17. The disc 15 is rotatable with respect to the casing I and it is formed with a cylindrical surface 18 which is in contact with needle bearings 19 disposed in an outer race 20, supported by the casing I. The disc 15 is also formed with a plane face 21, which acts as another frontal wall of the expansible chambers. The disc 15 has a number of holes 23, which are in fluid communication with an annular groove 24, which itself is in communication with the exhaust port 8.

That portion of the interior surface of the casing-part 3, which is between the surfaces 13 and 18, is formed with lobes, the top of each of the lobes being formed by pins 22. These lobes. act as gear teeth of a fixed member. The exterior surface of the orbiting member 14 is also formed with lobes, which act as gear teeth of the orbiting member. The number of lobes on the orbiting member is one less than the number of lobes on the fixed membenThe lobes of the fixed member and the lobes of the orbiting member are meshing and are designed to meet the gearing-and-bearing and sealing requirements of that conventional assembly well known in the art as gerotor.

A number of cylindrical pins 25 are fixed on both ends in holes formed in the shaft 9 and disc 15. The pins 25 pass through bushings 26 which are rotatably disposed in holes formed in the orbiting member 14. The surfaces of the pins 25 are in contact with the walls of the holes of the corresponding bushings 26 and transmit the rotation of the orbiting member 14 to the shaft 9, while still permitting the orbiting member to unobstructedly exhibit its orbiting motion.

The bushings 26 also function to reduce the friction between the pins 25 and the walls of the respective bushings 26 in which they are located, in that the bushings 26 rotate themselves in the holes in which they are placed, reducing the relative motion between themselves and the respective pins 25 with which they are in contact to a relative rolling of the walls of the holes of the bushings 26 on the surfaces of the pins 25.

While in the embodiment shown in FIGS. 1 to 4 of the drawings the pins 25 are fixedly attached to the shaft 9 and disc 15, and the orbiting member 14 is orbiting around them, it should be understood that, alternatively, the same kinematic result can be achieved by fixing the pins in the orbiting member and letting them orbit in holes formed in the shaft and disc assembly. The same kinematic result also can be achieved by placing the pins loosely or mounted in holding rings in relatively larger holes formed in the orbiting member, shaft and disc assembled with the shaft, so that the pins can perform a planetary motion relative to all parts which they are coupling.

The volume enclosed between two consecutive sealing contact-lines of the lobes of the fixed member and the lobes of the orbiting member and the surface of the lobes of the fixed member, the surface of the orbiting member and the facing surfaces 13 and 21 is defined herein as expansible chamber.

A number of cavities 30 are formed in the orbiting member 14, each of them corresponding with one of the expansible chambers described above. Each cavity 30 is connected by apertures 27 to the annular space between the shaft 9 and the wall of the central hole in the orbiting member 14. Each cavity 30 is also connected by apertures 29 to the corresponding expansible chamber. A valve assembly 31 is disposed in each of the cavities 30. The valve assembly is free to travel right and left from the position in which it is shown in FIG. 1, and thereby controls the flow of the driving fluid into and out of the expansible chambers. The valve assembly 31 has anextension which protrudes out of the cavity 30, being forced by a spring 32 against a corresponding control pin 33. The control pins 33 are fixed in holes formed in the shaft 9. An end face of the control pin 33 in contact with the extension of the valve assembly 31 is inclined as shown in FIG. 4, as is also the face of the extension of the valve assembly which is in contact and matching the inclined face of the control pin 33. Due to the relative motion of the orbiting member 14 relative to shaft 9, in a frontal view each point of the orbiting member 14 and the valve assemblies 31 describes a circular path relatively to the shaft 9 and control pin 33. Because the inclination of the end face of the control pins 33 and the inclination of the contacting end faces of the valve assemblies 31, the motion of the valve assembly 31 relative to the control pin 33 produces a reciprocating motion of the valve assembly 31, thereby controlling the flow of the driving fluid into and out of the expansible chambers.

Because at a given time the several valve assemblies 31 placed in the holes of the orbiting member 14 are generally in different phases of their respective reciprocating motion, a section taken along the line 3- 3 in the FIG. 1 cuts through the extensions of the individual valve assemblies at different distances from the center of their inclined faces and because of the inclination of the end faces, the area of the cuts through the extensions of the individual valve assemblies are different. This is clearly shown in FIG. 3 of the drawings.

It should be understood that, alternatively the control pins can be made adjustable and by modifying the position and/or inclination of their end faces in contact with the extensions of the valve assemblies, the position and motion of the valve assemblies can be modified as desired for a proper presetting or during the operation of the motor.

Each second exterior lobe of the orbiting member is cross-cut by the channels 34. The channels 34 are in fluid communication with the respective apertures 29 which connect them to the cavities 30. The contactlines of the non cross-cut lobes of the orbiting member 14 with the lobes of the fixed member act as seals for the expansible chambers.

In operation high pressure fluid from a fluid pressure supply (not shown) will flow via inlet port 7, through the holes 16 and 17 into the annular space between the shaft 9 and the orbiting member 14, and through the apertures 27 into the cavities 30. From these cavities the fluid is directed by the valve assemblies 31 through the apertures 29 and channels 34 into the correspond:

ing expansible chambers. The pressure of the fluid, acting upon that part of the lobes of the orbiting member 14 which enclose those expansible chambers which are expanding at that time, produces the motion of the orbiting member 14. The fluid exhausted from those chambers which are contracting at that time flows through the corresponding channels 34 and apertures 29 into the corresponding cavities 30. From there, the fluid is directed by the corresponding valve assemblies 31 through the central holes in the washers 28 and through the holes 23, and the groove 24 to the exhaust port 8.

The hydraulic motor B is shown in the FIGS. 5-8. It has a casing II consisting of parts 35, 36, 37, 38, 39, and 41, held together by fasteners 42. The end cap 35 has two openings extending through it, one being an inlet port 43 and another an exhaust port 44. A shaft 45 has a driven portion enclosed by the casing II and an output portion extending out through an opening in the end cap 41. The output portion of the shaft is provided with any conventional means not shown in the drawings for use in connecting the output portion to a load. The shaft 45 is rotatable with respect to the casing 11 and is formed with a cylindrical surface 46, which is in contact with needle bearings 47 disposed in an outer race 48 supported by the casing II. The shaft 45 has an extension which passes through a central hole in an orbiting member III, consisting of parts 49, 50 and 51, held together by means not shown in the drawings, the orbiting member III being placed eccentric with respect to the shaft 45 within the casing II. The end of the extension of the shaft 45 is fastened to a disc 52. The shaft 45 is also formed with a longitudinal hole 53 and transverse holes 54. The disc 52 is rotatable with respect to the casing II and it is formed with a cylindrical surface 55, which is in contact with needle bearings 56, disposed in an outer race 57, supported by the casing 11. The disc .52 has a number of holes 53 which are in fluid communication with an annular groove 59 which itself is in communication with the exhaust port 44. The parts 49 and 51 of the orbiting member III are formed with the plane faces 63 and 64 which act as frontal walls for a series of expansible chambers which will be hereinafter described.

The interior surfaces of the casing-parts 37 and 39 are formed with lobes, thetop of each of the lobes being formed by pins 58. These lobes act as gear'teeth of a fixed member. The exterior surfaces of the orbitset forth in the description of motor A, this leading to similar results as explained in the description of the motor A.

In operation, high pressure fluid from a fluid pressure supply (not shown) will flow via inlet port 43, through the holes 53 and 54 into theannular space between the shaft 45 and orbiting member III, and through the aperlobes do seal or do not seal is principally without importance. However, it should be understood, that possibility is provided for evacuation of the fluid which may be present in the diminishing volumes between the lobes of the fixed and orbiting members. I

A number of cylindrical pins 60 and 600 are fixed on one end in holes formed in the shaft 45 and in the disc 52. The pins 60 and 60a protrude into the holes of the bushings 61 and 61a which are rotatably disposed in holes formed in the orbiting-member-parts 49 and 51. The surfaces of the pins 60 and 60a are in contact with the walls of the holes of the corresponding bushings 61 and 61a. The kinematics of this arrangement is similar to that explained in the description of the motor A and the homologous parts have similar functions. It should be understood that, alternatively similar modifications of the arrangement of the pins, holes and bushings can be made as explained in the description of the motor A.

In the orbiting-member-part 50 there are formed a number of slots opened toward the exterior of the part. In each slot there is placed a sliding vane 62. By aid of means not shown in the drawings, the sliding vanes 62 are forced toward the exterior and pressed against the interior surface of the casing-part 38. The spaces between two consecutive sliding vanes 62 delimited by the exterior surface of the orbiting-member-part 50, the frontal surfaces 63 and 64, the interior surface of the casing-part 38 and the surface of those sliding vanes 62 constitute expansible chambers.

A number of cavities 65 are formed in the orbitingmember-part 50, each of them corresponding with one of the expansible chambers described above. Each cavity 65 is connected by apertures 66 to the annular space between the shaft 45 and the wall of the central hole in the orbiting member lll. Each cavity 65 is also connected by the apertures 69 to the corresponding expansible chamber. A valve assembly 70 is disposed in each of the cavities 65. The valve assembly 70 is free to travel right and left from the position in which it is shown in FIG. 4, and thereby controls the flow of the driving fluid into and out of the expansible chambers. The valve assembly 70 is forced by the spring 71 against corresponding interposed part 72, which is also free to travel right and left and is forced by the valve assembly 70 against a corresponding control pin 73. The

control pins 73 are fixed in holes formed in the shaft 45. An end face of the control pin 73 in contact with the interposed part 72 is inclined as shown in FIG. 8, as is also the face of the interposed part 72, which is in contact and matching the inclined face of the control pin 73. Hereinafter, (the claims inclusive), the interposed part will not be especially mentioned, and it should be understood that, the term valve assembly (or means) includes any such or similar interposed part if present. The kinematics of the arrangement is similar to that explained in the description of the motor A.

It should be understood that, alternatively, the control pins can be made adjustable in a similar way as that tures 66 into the cavities 65. From these cavities the fluid is directed by the valve assemblies through the apertures 69 into the corresponding expansible chambers. The pressure of the fluid acting upon the orbitingmember-part 50 produces the motion of the orbiting member III. The action of the fluid upon the orbitingmember-part 50 occurs in two ways, directly and indirectly. The word directly is used to point out that the fluid acts directly upon the surface of the orbiting-- member-part 50. The word indirectly is used to point out that the fluid acts primarily upon sliding vanes 62, the resulting force being transmitted to the orbitingmember-part 50 by the contact surfaces between the sliding vanes 62 and the orbiting-member-part 50.

It should be understood that, alternatively to the sliding vane arrangement described, other vane-type or cylinder-piston type, or other type of arrangements,

also can be used to form and seal expansible chambers, the driving fluid contained in the expansible chambers acting directly and/or indirectly upon the orbiting member and causing its motion.

The fluid exhausted from those chambers which are I contracting at that time, flows through the corresponding apertures 69 into the corresponding cavities 65. From there, the fluid is directed by the corresponding valve assemblies 70 through the holes 67 and through the holes 68 and the groove 59 to the exhaust port 44.

I claim: 1. A fluid pump or motor comprising: a casing having inlet and outlet cavities; a shaft mounted for rotation with respect to said casa gerotor comprising a stator fixed in respect to said casing and having a plurality of teeth concentric to the axis of said shaft, and a rotor mounted for relative rotation and orbital movement within said stator and having teeth offset with respect to the shaft axis cooperating with said teeth of said stator to define a plurality of expanding and collapsing fluid chambers around said shaft axis; wall means for closing opposite ends of the chambers between the teeth of the stator and the teeth of the orbiting rotor; drive means for coupling said shaft to said orbiting rotor to rotate and orbit the same upon rotation of said shaft; and valve means including a plurality of reciprocating valves moving in response to the relative position of said rotor in said stator for connecting said one of said cavities with expanding ones of said chambers and connecting the other of said cavities with collapsing ones of said chambers, each of said valves reciprocating within a cylinder having spaced wall ports in communication with said inlet and outlet cavities. 2. The fluid pump or motor of claim 1 wherein said valve cylinders are longitudinally parallel of said shaft axis spaced radially outward thereof.

3. The fluid pump or motor of claim 1 wherein said valves comprise elongated pistons slidable longitudinally in said cylinders, and means for resistently biasin g said valves toward one end of said cylinders.

4. The fluid pump or motor of claim 3 including valve actuator means responsive to the position of said motor in said stator engaging end surfaces of said valves for moving the same in said cylinders against said biasing means.

5. The fluid pump or motor of claim 3 wherein said valve cylinders are formed with wall ports in communication with said fluid chambers.

6. The fluid pump or motor of claim 3 wherein each valve is formed with an annular groove intermediate the ends for selective communication with at least one of said wall ports in response to the position of said valve in its cylinder.

7. The fluid pump or motor of claim 6 wherein one of said wall ports in each cylinder is positioned at an end of said cylinder.

8. Hydraulic motor or pump comprising:

a casing having inlet and outlet ports;

a shaft supported by said casing and rotatable with respect thereto;

a gerotor comprising a fixed member, fixed in respect to said casing and having a plurality of teeth concentric to said shaft, and an orbiting member movably mounted within said fixed member and having teeth offset with respect to said shaft;

means for sealing the frontal ends of the volumes between the teeth of the fixed member and the teeth of the orbiting member, forming a set of ex pansible chambers, said expansible chambers being in fluid communication with said inlet and outlet ports;

coupling means for coupling said shaft to said orbiting member;

valve means comprising a plurality of reciprocating valves located between said expansible chambers and said ports for controlling the flow of the fluid between said inlet port and one part of said set of expansible chambers and between the exhaust port and a second part of said set of expansible chambers, and valve control means having cam means engaged in sliding contact with end faces of said valves, said valves and said cam means movable relative to one another in an orbiting motion for causing reciprocating motion of said valves with respect to saidchambers and said ports between which said valves are disposed.

9. The motor of claim 8 wherein said valves are driven with an orbiting motion in respect to said cam means of said valve control means, said valves carried by said gerotor and movable in a reciprocating motion with respect to said gerotor to direct fluid flow between said ports and said chambers.

10. The motor of claim 8 where said end faces of each valve in sliding contact with said cam means are inclined relative to the axis of reciprocation of said valves, whereby said orbiting motion of said valves with respect to said cam means moves said valves in reciprocating motion.

11. The motor of claim 10 wherein a major portion of said valves are disposed in said orbiting member.

12. The motor of claim 8 wherein sal cam means in sliding contact with said valves includes inclined surfaces engaging those of said valves whereby said orbiting motion impels reciprocating motion of said valves.

13. The motor of claim 12, wherein a major portion of said valves are disposed in said orbiting member. 

1. A fluid pump or motor comprising: a casing having inlet and outlet cavities; a shaft mounted for rotation with respect to said casing; a gerotor comprising a stator fixed in respect to saiD casing and having a plurality of teeth concentric to the axis of said shaft, and a rotor mounted for relative rotation and orbital movement within said stator and having teeth offset with respect to the shaft axis cooperating with said teeth of said stator to define a plurality of expanding and collapsing fluid chambers around said shaft axis; wall means for closing opposite ends of the chambers between the teeth of the stator and the teeth of the orbiting rotor; drive means for coupling said shaft to said orbiting rotor to rotate and orbit the same upon rotation of said shaft; and valve means including a plurality of reciprocating valves moving in response to the relative position of said rotor in said stator for connecting said one of said cavities with expanding ones of said chambers and connecting the other of said cavities with collapsing ones of said chambers, each of said valves reciprocating within a cylinder having spaced wall ports in communication with said inlet and outlet cavities.
 2. The fluid pump or motor of claim 1 wherein said valve cylinders are longitudinally parallel of said shaft axis spaced radially outward thereof.
 3. The fluid pump or motor of claim 1 wherein said valves comprise elongated pistons slidable longitudinally in said cylinders, and means for resistently biasing said valves toward one end of said cylinders.
 4. The fluid pump or motor of claim 3 including valve actuator means responsive to the position of said motor in said stator engaging end surfaces of said valves for moving the same in said cylinders against said biasing means.
 5. The fluid pump or motor of claim 3 wherein said valve cylinders are formed with wall ports in communication with said fluid chambers.
 6. The fluid pump or motor of claim 3 wherein each valve is formed with an annular groove intermediate the ends for selective communication with at least one of said wall ports in response to the position of said valve in its cylinder.
 7. The fluid pump or motor of claim 6 wherein one of said wall ports in each cylinder is positioned at an end of said cylinder.
 8. Hydraulic motor or pump comprising: a casing having inlet and outlet ports; a shaft supported by said casing and rotatable with respect thereto; a gerotor comprising a fixed member, fixed in respect to said casing and having a plurality of teeth concentric to said shaft, and an orbiting member movably mounted within said fixed member and having teeth offset with respect to said shaft; means for sealing the frontal ends of the volumes between the teeth of the fixed member and the teeth of the orbiting member, forming a set of expansible chambers, said expansible chambers being in fluid communication with said inlet and outlet ports; coupling means for coupling said shaft to said orbiting member; valve means comprising a plurality of reciprocating valves located between said expansible chambers and said ports for controlling the flow of the fluid between said inlet port and one part of said set of expansible chambers and between the exhaust port and a second part of said set of expansible chambers, and valve control means having cam means engaged in sliding contact with end faces of said valves, said valves and said cam means movable relative to one another in an orbiting motion for causing reciprocating motion of said valves with respect to said chambers and said ports between which said valves are disposed.
 9. The motor of claim 8 wherein said valves are driven with an orbiting motion in respect to said cam means of said valve control means, said valves carried by said gerotor and movable in a reciprocating motion with respect to said gerotor to direct fluid flow between said ports and said chambers.
 10. The motor of claim 8 where said end faces of each valve in sliding contact with said cam means are inclined relative to the axis of reciprocation of said valves, whereby said orbiting motion of said valves with respect to said cam means moves saId valves in reciprocating motion.
 11. The motor of claim 10 wherein a major portion of said valves are disposed in said orbiting member.
 12. The motor of claim 8 wherein said cam means in sliding contact with said valves includes inclined surfaces engaging those of said valves whereby said orbiting motion impels reciprocating motion of said valves.
 13. The motor of claim 12, wherein a major portion of said valves are disposed in said orbiting member. 